Replacement King Kutter Finish Mower Gearbox, code 184000, fits King Kutter models RFM48-72.  40hp rated, 1-3/8" smooth input shaft with 1/2" shear bolt hole and circlip groove (circlip included), 1.57" X 12 tapered spline output shaft and 1:1.93 speed up ratio. Fits all King Kutter finish mowers except for the RFM-84 84" cut models which use the 184005 gearbox that can be purchased from pour store.